VIENNA (Reuters) - Austrian Chancellor Christian Kern’s center-left SPO party said a survey had shown broad popular support for his criticism of a free trade deal between the European Union and Canada only weeks before the accord seen as a blueprint for a trade project with the United States was due to be signed.

Negotiations on the EU-Canada pact known as CETA have finished, but social democrat Kern has been lobbying for last minute promises from Brussels and Ottawa to curtail the use of investment courts which he says investors could use against governments.

Kern’s SPO, leading a coalition government with the conservative OVP which approves of the CETA deal, said its survey of around 24,000 Austrians showed 88 percent wanted Austria to oppose CETA going into force even provisionally.

Kern’s party published the results on Tuesday hours after its German sister party SPD voted in favor of backing CETA, which aims to eliminate tariffs on 98 percent of goods immediately and encompasses regulatory cooperation and access to government tenders.

In the German case, the social democrats won over CETA critics with a compromise that calls for the European Parliament to launch a consultation process before a decision is taken on what parts of CETA should be applied provisionally.

OVP leader and Economy Minister Reinhold Mitterlehner said a binding declaration clarifying contentious issues attached to the deal could be the way to a joint coalition line.

The SPO’s survey, which included around 10,000 non-SPO members, showed 92 percent were critical of CETA being applied in Austria if it includes a mechanism which allows companies to sue governments if they feel disadvantaged by regulation.

The European Commissioner on Trade said last week in Vienna it was unlikely that such courts would come into use during the envisaged provisional implementation of CETA from early next year after a signing ceremony due on Oct. 27.

No decision has been reached yet to clarify what exactly provisional implementation will entail, however.

CETA will require the approval of the European Parliament before taking effect, prior to ratifications by national parliaments which could take five years or more.

Austria’s economy minister, as well as German and French ministers, has also called for a restart of talks on a free trade pact between the EU and the United States, or TTIP, which have stalled.